Several experts are concerned that the public is now getting an incomplete picture of the vaccine candidate’s efficacy and that critical information has not been published, including which demographic groups are protected and whether the subjects are also covered for the heavier variants of the vaccine. new coronavirus have been saved. There is also a real chance that the 90 percent conscious percentage will change as the test continues and researchers get more data. In addition, the unpublished results have not yet been reviewed by other scientists or even appeared as preliminary preprint.
“The lack of data is very concerning,” says Peter Doshi, assistant professor of pharmacological care in the University of Maryland’s Department of Pharmacology. “All we have right now is a Pfizer headline.”
But other experts praise the decision, and consider it unlikely that the 90 percent result will change significantly over time. “It will probably shift a bit, but then you are talking about 87 percent. Given the numbers they got during the test, it can’t be fifty percent, ”says Robert Wachter, dean of the University of California San Francisco School of Medicine, researching patient safety. “It’s clearly close to ninety percent.”
Hooks and eyes
Here’s how the Phase 3 trial for the Pfizer and BioNTech vaccine candidate works: This third and final phase began in July, when researchers divided a total of 43,538 subjects into two groups. One group was given the vaccine, the other group a non-working substance, or a placebo. According to it protocol of the test the candidate vaccine is administered in two doses, two weeks apart. The researchers waited at least seven weeks after administering the second dose to assess who became infected with the coronavirus in real life. It was assumed that the subjects of both groups engaged in the same type of activities and took approximately the same risks.
In order for Phase 3 testing to be as unbiased as possible, pharmaceutical companies are usually ‘blind’ to these types of tests: they are not notified of the results that come in. But an exception is made for testing a target vaccine against COVID-19: every so often it is reported how many volunteers have contracted the disease. At these ‘milestones’, the independent panel overseeing the test – the ‘data monitoring committee’ – can tell a company how things are progressing. Pfizer and BioNTech were now able to announce their promising result because the Phase 3 trial had reached one of these “milestones” – involving 94 cases of COVID-19.
But the preliminary results do not indicate which of these patients received the vaccine and for whom it did not work. It also concerns data that only concerns a small part of the total number of test subjects tested. But Wachter thinks he can deduce from the press release that about nine COVID-19 cases occurred in the vaccinated group and about ninety in the placebo group.
By not fully disclosing the results, the companies run the risk that the press release will send a misleading message that “the vaccine offers more protection than it actually provides,” said Doshi, who is researching authorization protocols for new drugs. “Pfizer has not yet published anything to suggest that the 90 percent efficacy rate also applies to the most vulnerable groups, such as the elderly and people in nursing homes.”
It is also unclear whether the candidate vaccine only protects against symptoms in mild or less severe cases, or also in more severe disease courses. That kind of information is very important because ideally a vaccine should lead to a reduction in deaths, hospitalizations and ICU treatments. “The study should provide insight into the severity of the disease course, but all they’re looking at are symptoms,” says Maria Elena Bottazzi, co-director of the Center for Vaccine Development at Texas Children’s Hospital in Houston.
It is not known whether the 94 COVID-19 patients also included people with underlying syndromes. That data is important because health authorities will prioritize the distribution of the first vaccines risk groups and socially vulnerable citizens. “The test does not reveal who received the vaccine,” says Paul Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia and member of the US FDA’s advisory committee for COVID-19. “You wonder whether these risk groups were well represented.”
The final work?
The news about the candidate vaccine made the stock exchanges spring up, making the negative trend from the past weeks was undone. But this response also raises the question of why Pfizer and BioNTech decided to release their “interim report” to the world. When asked whether Pfizer may have been pressured by shareholders, Jerica Pitts, Pfizer’s global director of information, replies that the company was under no obligation to make the report public, but that it always intended to.
“We said from the outset that we would share the interim results, given that a breakthrough is eagerly awaited,” Pitts wrote in an email to National Geographic. “We have made it clear that these results are not definitive and only concern participants who have not previously been infected with the coronavirus or contracted COVID-19.”
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